Hepatitis B: Progress in the Last Decade

Hepatitis B virus (HBV) was the first to be discovered among hepatitis viruses. As with many other discoveries in science, identification of the causative agent of hepatitis B was fortuitous. Following the discovery of the Australia antigen and its subsequent association with serum hepatitis in the 1960s,[1] [2] significant advances in our knowledge of hepatitis B were made in the 1970s and 1980s. The hepatitis B virion (Dane particle) was visualized,[3] the HBV genome was sequenced, and the asymmetric replication of HBV DNA was unraveled.[4] Additional hepatitis B antigens and antibodies were identified, and serologic and later molecular diagnostic tests were developed. Application of these tests led to elimination of transfusion-related hepatitis B, understanding of the spectrum of hepatic and extrahepatic manifestations of HBV infection, and establishment of the etiologic role of chronic HBV infection in the development of hepatocellular carcinoma.[5] Many antiviral and immunomodulatory agents were evaluated for the treatment of chronic hepatitis B, but only interferon-alpha had sufficient safety and efficacy to be an accepted treatment by the late 1980s. The most important advance in the 1980s was the development of hepatitis B vaccines and the demonstration that these vaccines were safe and effective in preventing HBV infection.[6] The implementation of HBV vaccine programs led to dramatic reduction in HBV carrier rate among children in endemic areas and in HBV infection among healthcare workers.

Hepatitis B research took a back seat in the 1990s, being overshadowed by hepatitis C. Investigators left and research funding dwindled, in part because there is more excitement in studying a new disease and a virus that had eluded researchers for two decades. In addition, it was thought that all that would ever be known about hepatitis B was already known and, with the availability of vaccines, hepatitis B would be a rapidly declining disease. The readers of this issue of Seminars in Liver Disease may be amazed at how much progress has been made in hepatitis B in the past decade. It will also be obvious that much remains to be learned about this ancient, intriguing, and still prevalent disease.

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